This study will evaluate participants in the MacArthur Study on Successful Aging to examine how Apolipoprotein E (ApoE) status influences cognitive and physical decline, cardiovascular disease incidence and mortality, and all-cause mortality in a representative sample of older persons who initially had high cognitive and physical functioning. The analyses are based on evidence suggesting that ApoE4 genotype is associated with increased risk for Alzheimer's disease, cardiovascular disease and longevity in general as well as more suggestive evidence that it may also be associated with more general risks for cognitive decline and functional disability. Data on ApoE genotype for the MacArthur Successful Aging cohort is being obtained through analyses of stored DNA samples. These samples were originally collected in 1988 at the beginning of the study. Previous analyses of collected blood and urine samples have included assays for cholesterol, DHEA-S, glycosylated hemoglobin, homocysteine and folic acid levels as well as urinary cortisol and catecholamines. Additional, existing information int he MacArthur database includes sociodemographic, health status, health behaviors, psychosocial characteristics and detailed assessments of both physical and cognitive functioning. Data are now available for an 8-year follow-up period (1988-1996), including detailed information on patterns of change in cognitive and physical functioning, prevalence and incidence of cardiovascular disease and overall mortality. Cohort diversity with respect to gender, ethnicity, educational attainment and behavioral characteristics such as individuals' health behaviors (e.g., exercise, smoking) also provides sufficient numbers of individuals for proposed analyses of possible ApoE interactions with these characteristics.